Some phosphorus containing derivatives of alkyl acetothiolacetate



SOME PHOSPHORUS CONTAINING DERIVATIVES OF ALKYL ACETOTHIOLACETATE Thomas P. Dawson, Bel Air, Md., Elwyn R. Lovejoy,

Wilmington, Del., and Charles E. Williamson, Edgewood, and Benjamin Witten, Baltimore, Md.

No Drawing. Application March 9, 1956 Serial No. 570,644

14 Claims. (Cl. 167-22) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to us of any royalty thereon.

This invention relates to new phosphorus-containing derivatives of alkyl acetothiolacetates, the process of manufacturing those compounds, and the use of the compounds as insecticides.

.More particularly it relates to O-[2-(alkylthio) carbonyl-l-methylvinyl] 0,0-dialkyl phosphates, O-[2-(alkylthio carbonyl-l-methylvinyl] 0,0-dialkyl phosphorothioates, O-[2-(alkylthio)carbonyl 1 methylvinyHO-alkyl i arylphosphonates and O-[2-(alkylthio)carbonyl-l-methylvinyl] O-alkyl arylphosphonothioates.

Our compounds may be represented by the following general formula 1 v 1 vitwi --o -o=oH ":sR"

a R CH3 'wherelR is anaryl'group containing 6 to 9 carbon atoms or an alkoxy-group containing not more than 6 carbon i .1

atoms,- R is alkyl group containing not more than 6 carbon atoms, R" is an alkyl group containing not more than 10 carbon atoms, and X is oxygen or sulfur.

These compounds are highly effective insecticides.

They combine extremely high toxicity toward insects with low mammalian toxicity.

The present invention also includes a process for the manufacture of the above compounds. 'We react an alkyl acetothiolacetate, e.g. ethyl acetothiolacetate I clzt -co-onri lsozm with a dialkyl phosphorohalidate, e.g. diethyl phosphorochloridate T QgHrO-P Cl OCaHs a dialkyl phosphorohalidothioate, e.g. 0,0-diethyl phosphorochloridothioate an alkyl arylphosphonohalidate, e. g. ethyl phenylphosphonochloridate 0 T 1|Cl or an alkyl arylphosphonohalidothiate, e.g., O-ethyl phenylphosphonochloridothioate 2,913,367 Patented Nov. 17, 1959 depending whether R is alkoxy or aryl and whether X is oxygen or sulfur. The reaction is carried out in the presence of an amine-type HCl acceptor, preferably triethylamine.

Alternatively, an alkali metal derivative of the proper acetothiolacetate may be reacted with the proper dialkyl phosphorohalidate, dialkyl phosphorohalidothioate, alkyl arylphosphonohalidate, or alkyl arylphosphonohalidothioate.

In either case the reaction is preferably conducted in an anhydrous inert solvent, e.g., benzene, xylene, hexane,

or other low-boiling hydrocarbon or hydrocarbon fraction.

The preferred halidates and halidothioates for the introduction of the phosphorous-containing radical are the chloridates and chloridothioates, respectively. Examples of preferred reagents of these classes are as follows:

(A) Dialkyl phosphorochloridates:

Examples of preferred alkyl acetothiolacetates are:

Methyl acetothiolacetate Ethyl acetothiolacetate n-Propyl acetothiolacetate I Isopropyl acetothiolacetate n-Butyl acetothiolacetate The following is a representative example of the production of our compounds:

EXAMPLE I 0,0-diethyl O-[Z-(ethylthio)carbonyl-1 -methylvinyll v phosphorothioate 0,0-diethyl phosphorochloridothioate (9.4 g., 0.05 M), and ethyl acetothiolacetate (7.3 g., 0.05 M), and triethylamine (10 g., 0.1 M) were dissolved in ml. of benzene and the mixture was refluxed for one hour. It was removed and washed with water (4X50 ml.), and then the solvent was removed by distillation at reduced pressure. A yield of 7.2 g. (=48.3%) of product remained.

Other particularly preferred compounds of our inven tion that may be prepared by the same general method, utilizing the proper reactants are:

0,0-diethyl O-[2-(rnethylthio)carbonyl 1 methylvinyl] phosphorothioate O ethyl O [2 (ethylthio)carbonyl 1 methylvinyl] phenylphosphonothioate O ethyl 0 [2 (methylthio)carbonyl -1 methylvinyl] phenylphosphonothioate 0,0 diethyl O [2 (ethylthio)carbonyl l methylvinl] phosphate 0,0 diethyl O [2 (methylthio)carbonyl 1 methylvinyl] phosphate ethyl O [2 (ethylthio)carbonyl 1 methylvinyl] phenylphosphonate O ethyl O [2 (methylthio) carbonyl 1 methylvinyl] phenylphosphonate 0,0 dimethyl O [2 (ethylthio)carbonyl 1 methylvinyll phosphorothioate O methyl 0 [2 (ethylthio)carhonyl 1 methylvinyl] phenylphosphonothioate O methyl 0 [2 (methylthio)carbonyl 1 methylvinyllphenylphosphonothioate 0,0 dimethyl O [2 (ethylthio)carbonyl l methylvinyl] phosphate 0,0 dimethyl O [2 (methylthio)carbonyl 1 methylvinyl 1 phosphate 0 methyl 0 [2 (ethylthio)carbonyl 1 methylvinyl] phenylphosphonate 0 methyl 0 [2 (methylthio)carbonyl 1 methylvinyl] phenylphosphonate These particularly preferred compounds are those in which, referring to the general formula, R is methoxy, ethoxy or phenyl, R is methyl or ethyl, and R is methyl or ethyl.

The following example illustrates the insecticidal properties of one of our preferred compounds.

EXAMPLE II A 1% acetone solution of 0,0-diethyl O-[Z-(ethylthio) carbonyl-l-methylvinyl]phosphorothioate was prepared. One milliliter was placed in a one liter bottle and the acetone allowed to evaporate. In another bottle was placed one milliter of a 1% solution of malathion, from.

which the acetone was also allowed to evaporate. The same number of the same variety of cockroaches were then placed in each bottle and timed to death. Those in the bottle containing the phosphorothioate died considerably more quickly than those in the bottle containing malathion.

The other compounds of our group may be prepared in the same manner (substituting the proper reagents), and used in the same manner, as the compound prepared and used in Examples 1 and 2. Numerous other solvents, e.g. low-boiling hydrocarbons or water may be employed instead of acetone, and the compounds may also be employed in dusting powders and other insecticidal compositions.

We claim: 1. A compound of the formula X 0 T ll RPOC=CH-CSR" R being selected from the class consisting of aryl groups containing from 6 to 9 carbon atoms and alkoxy groups containing not more than 6 carbon atoms, R is an alkyl group containing not more than 6 carbon atoms, R is an alkyl group containing not more than ten carbon atoms, and X is selected from the class consisting of sulphur and oxygen.

2. 0,0 diethyl O [2 (ethylthio)carbonyl 1- methlvinyl] phosphorothioate.

3. 0,0 diethyl O [2 (ethylthio)carbonyl 1- methylvinyl phosphate.

4. 0,0 dimethyl O [2 (ethylthio)carbonyl lmethylvinyl]phosphorothioate.

5. 0,0 dimethyl O [2 (ethylthio)carbonyl 1- methylvinyllphosphate.

6. 0,0 dimethyl 0 [2 methylvinyl] phosphorothioate.

7. 0,0 dimethyl 0 [2 (methylthio)carbonyl 1- methyl vinyl] phosphate.

8. A method of killing insects which comprises contacting them with a compound as defined in claim 1.

9. A method of killing insects which comprises contacting them with a compound as defined in claim 2.

10. A process of killing insects which comprises contacting them with a compound as defined in claim 3.

11. A method of killing insects which comprises contacting them with a compound as defined in claim 4.

12. A method of killing insects which comprises contacting them with a compound as defined in claim 5.

13. A method of killing insects which comprises contacting them with a compound as defined in claim 6.

14. A method of killing insects which comprises contacting them with a compound as defined inv claim 7.

(methylthio)carbonyl 1- References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES BIOS Final Report 714 (revised) (RB. 87, 923 R), p. 53 (1948).

Pudovik et al.:

Doklay Nauk S.S.S.R., vol. 105, pp. 735-7 (1955). 

1. A COMPOUND OF THE FORMULA 